Tracheids are long cells in the xylem of vascular plants. They transport water and mineral salts. Tracheids are one of two types of elements in the xylem, vessel elements being the other. Tracheids do not have perforation plates; vessel elements do.[1] These define vascular plants, as opposed to non-vascular plants.
.png)
All tracheary elements get a thick lignified cell wall. When the plant is mature, the protoplast has broken down and disappeared.[2] Tracheids have two functions. They transport material and provide structural support.
The secondary walls have thickenings in various forms: rings, spirals, networks or as extensive thickenings except where there are pits.[3] Tracheids provide most of the structural support in softwoods, where they are the major cell type.
Because tracheids have a much larger surface area to volume ratio compared to vessel elements, they hold water against gravity (by adhesion) when transpiration is not occurring. This mechanism helps plants prevent air embolisms.
The term "tracheid" was introduced by Carl Sanio in 1863, originally as Tracheide, in German.[4]
Wikiwand in your browser!
Seamless Wikipedia browsing. On steroids.
Every time you click a link to Wikipedia, Wiktionary or Wikiquote in your browser's search results, it will show the modern Wikiwand interface.
Wikiwand extension is a five stars, simple, with minimum permission required to keep your browsing private, safe and transparent.
